Originally Posted by HavocSteve
Hmmmm... sounds like it might be crank related if it changes with revs.
This is what I'm worried about. I'm not sure what I can do to isolate a particular area of the motor (head, crankcase, VANOS, etc.) so I know what to fix. Using the stethoscope indicates the noise is coming from the front of the motor, and it sounds like a spinning bearing. Though I'm not sure how to confirm.
As for the idler pulley, that might be the case, I will have to check those out. However, it sounds like it's coming from within the motor.